4-cell embryo,light micrograph. The development of an embryo is called embryogenesis. In organisms that reproduce sexually,once a sperm fertilizes an egg cell,the result is a cell that has all the DNA (deoxyribonucleic acid) of the two parents (zygote). The zygote begins to divide by mitosis producing 2,4,6,8 cells and so on,to form a multicellular organism. The zygote is called an embryo from the first cell division,up until the end of the 8th week,whereafter it is instead called a foetus | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Layyous, Dr. Najeeb |
Bildgröße: | 3260 px × 2717 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |